Pneumatic concentrating-table.



C. YNE.

PNEUMATICC T'RATING TABLE.

APPLICATION FILED AUG. 18. l9l6.

Patented Jan..16,1917.

2 SHEETS-SH EET 2.

CLARENCE Q. PAYNE, OF NEW YORF N. Y.

PNEUMATIC CONCENTRATING-TABLE.

Specification of Letters Patent.

Patented Jan. 16, M111.

Application filed August 18, 1916. Serial No. 115,590.

To all "whom it may concern:

Be it known that I, CLARENCE Q. PAYNE, a citizen of the United States of America, residing in the borough of Manhattan, city, county and- State of New York, have ipvented certain new and useful Improvements in Pneumatic Concentrating Tables, of which the following is a full and true description.

My invention relates to improvements in that type of concentrating table which separates associated minerals from each other, or crushed ores from their gangues, in a dry state, by reason of differences in their specific gravities, when they are acted on by air.under pressure while being subjected to mechanical agitation.

It consists in the combination of a novel and improved form of table top with improved means for separating minerals of difterent'specific' gravities, after they have been arranged in layers or strata by means of air pressure and mechanical agitationupon the surface of said table top.

In a patent numbered 1,068,163, granted to me July 22,1913, I have described and claimed a novel medium for the pervious top of a pneumatic concentrating table, whereby greater durability, as well as more uniformeffects, are procured in the treatment and separation of various ore.mixtures.

My present application is a modification and improvement of the above mentioned patent, and is specifically concerned with a new and useful combination of means for removing the separated products from the table after they have been stratified, with the aforesaid novel and durable top, whereby a more efiicient and satisfactory separation is obtained than has heretofore been possible. i

In the accompanying illustrations Figures 1 and 2 show a concentrating table in part sectional elevation and. plan, in

which my invention is embodied. Fig. 3

shows a sectional view across the-table top. Fig. 4 ilustrates a portion of the tabledeck on a larger scale than Fig. 1, and Fig. oillustrates diagrammatically the principle involved in my invention. Figs. 3 and 5 are illustrations of Fig. 1 on an enlarged scale. v

In Figs. 1 and 2 the form of concentrating table illustrated is so designed that the table deck can be given an inclination both in a longitudinal direction, and also in a transverse direction, so that the stratified products may be separated from each other in distinct bands, conveyed lengthwise of the table by the shaking motion of the tabla-and then collected at the end and side of the table as indicated in Fig. For this purpose the table is supported by any convenient tilting mechanism, such as shown in Figs. land 2. Here the upper end of the table is held by a sleeve, or short hollow 1 shaft 10 in the bracket support 11 to the foundation frame 12. The end of'sleeve 10 supports the bracket 13, which rotates about it and to which is bolted the spring-plate 14. The latter in turn supports the bearings 15, '15 at its extreme ends, and these support the ends of the shafts 16, 16 which are held by brackets 17, 17 to the deck frame of thetable.

The bracket 13 has an extension on its 'lower side, which carries the segment of a worm wheel.

The latter engages a worm which is mounted on the shaft 18, and is revolved by means of the hand-wheel 1 9. In this way the table deck can betilted trans- -versely to a considerable angle by the rotation or" the hand-wheel while at the same time it can be moved rapidly back and forth by the slight bending of the spring plate 14 at its ends, which supports about one-half the weight of the table.

The lower end of the table may be preferably supported by a single hinged rockerarm, or shaft, sons to obtain, in effect a.

box is inclosed by a thin sheet iron plate table-deck can be given an inclination 1ongitudinally as well as transversely. A reciprocating motion rnay be conveniently im-. parted to the table-deck by means of a cam 24, or other suitable device for giving it a slow forwardand quick return motion, the object being to agitate and also propel the material fed upon the table-deck rapidly lengthwise of the table.

As shown in Fig. 1 the cam 21 is mounted upon the shaft 25, and raises the roller 26, which rotates upon a shaft held in the bellcrank-lever 27, to which the connecting rod 28 is attached. This connecting rod is held at its other end to the pivoted bracket 29, which is riveted to the end of the table frame. To absorb the shock of the rapid reversal of the table-deck, and to maintain the roller 26 always in contact with the cam 2 spiral springs 30, 30 are supported between fixed abutments on the bracket 11 and wings on the bell-crank-lever'27. The compression of the springs can be varied by means of suitable bolts and washers as shown in Fig. 2. The amount of motion to be given the table-deck and the speed of the latter or number of shakes per-minute, will vary with the degree of fineness of the material to be treated.

The table-deck of my concentrating table, as shown in part section in Fig. i, and the cross section in Fig. l, is composed of porous silica plates 31, or a like mineral septum, through which air under pressure is made to pass. The joints and ends of the plates are carefully cemented so that the air from the inclosure below them can only pass through the body of the plates plates are supported by means of light T irons 32, which are riveted to-the channel iron frame of the table. The latter forms the four sides of a box. of which the silica plates form the top. The bottom of the closely riveted to the channel iron flanges so as to make air tight joints. Air is ad mittedto the under side of the concentrat ing table by means of a pipe 34, which is connected with a pressure fan, not shown in the drawings.

The table is fed at its upper end from any convenient hopper- 35. The ore-mixture should be carefully sized in advance, de pending however on the ditferencc in the specific gravity of the minerals to be separated. As it is caused to travel lengthwise of the table by the quick return stroke of the latter, the.combined effect of the upward air currents through the fine pores and openings of the silica plates, or similar mincral septum, with the agitation due tothe shaking motion'of the table, causes the minerals of the ore mixture to separate and to occupy supcrposml layers or strata on the table-deck, the hcavy mineral forminvention,

resistant. to through the mineral septum, the a "as indicated in These I rountercd,

ing the lower layer while the light mineral forms the upper layeiyas indicated in the shaking motion can induce the layers to lie along divergent paths of travel as they are conveyed diagonally across the table top under the combinedinfluence of the shaking motion the side tilt of the table-deck. This result can be secured is accordance with my invention by causing certain portions of t ininerai septum to be made imp'er ions to air along narrow areas spaced lengthwise of the table-deck.

A nvenient construction, embodying my consists in cutting shallow grooves 36, 36 in the top of the mineral septum which forms the table-deck, and then filling these grooves with an impervious cement flush with the surface of the table deck as shown in Fig. 3. For t purpose Portland cement may be en'uiloye orany similar cement whose ingredient. approximately as hard as the mate the mineral septum itself, so as to be wear. In passing obstructed along the areas of ihe i2 grooves. The latter n'iay he 3a. parallel with the longitudinal motion of the table. or prefcra 'ut angle to it,

Fig. 5 illustrates iiagrammatically more clearly the resulting effect of my invention in causing the separation of superposed layers of minerals to pursue different rates of flow; sents the heavier mineral, and the upper shaded area the light mineral, which have thus been stratified by the joint action of mechanical agitation and the sorting action of air under pressure passing through the ore-mixture. The underlying"principle involved in this stratifying effect is that of hindered settling". When the oresheet thus st'atified encounters one of the impervious areas of the table-deck", its lower portion more retarded in passing over it than its upper portiom This is partly due to the greater frictional resistance there'enpartly to the more complete cessation of the lifting effect of'the air at the bottom than at the top of the ore-sheet,

illustrate the combined forces thus actingon a particle situated at A. by the line A B, and on a. particle at by the line C D, we can thus illustrate diagraimnatically the The lower shaded area here repre cause a separating action between the upper and lower strata, by establishing a difference in their rate of movement across these areas. By repeat-in this action a great many times in causing: the ore sheet to pass diagonally across a series of alternately pervious and impervious areas of the table-deck, I have found that a very efficient separation can be made between minerals of different specil'ic gravi'ties.

The operation oi? my table is as follows: Air from a pressure fan is conveyed through a pipe 3-1 to the inclosure below the table deck. and is then allowed to pass through the perviousmineral septum of the tabledcck under a regulated pressure. At the same time the table while in a transversely inclined position, is ven a rapid reciproeating motion by means of the cam and lever, or similar head motion mechanism, driven by a belt from an outside source of power. The material to be separated is fed in a dry state in a regulated stream from a hopper It is preferably first sized before it is fed upon the table; e., it is passed over screens in order to reduce the difference in the diameters of the particles to a predetermined ratio. In traveling lengthwise, and across the inclined surface of the table-deck, the ore-mixture encounters a series of alternately pervious and impervious areas of the mineral septum which forms the surface of the table. -While passing over the t'orn'ier, the combined action of the upward air current and the mechanical agitation of the particles, due to the shaking motion of the table, causes the heavier particles to'settle through the agitated mass, and form the bottom layer of the ore-sheet resting on the table deck. The lighter particles, on the other hand, work their way upward and formthe top layer of. the ore-sheet as indicated in the sketch Fig. In passing over the impervious areas of the table-deck, however, the stratifying action is temporarily interrupted, and a ditt'eience in the rate of travel between the upper and lower layers of the ore-sheet is established. This causes the upper and owcr layers to progress along divergent pal hs 01 travel as they are propelled lengthwise ot' the table-deck. These ellects being repeated a great many times byreason of the subdivision oi the surface into alternatel-y pervious and impervious areas. the ditl'erent minerals composing the ore-sheet are separated from each other, and made to travel in radiating bands. as shown in the )lan view of the table in Fig. '2, by the areas ounded by the broken lines. The separated products are then collected by the guide-pieces whose position can be adjusted along the end and lower side of the table, as shown in 2, and discharged into different receptacles. In order to maintain a suitable thickness of the ore-sheet along its upper edge where the heavy mineral cot lects, l have found it desirable to employ banking strips for this purpose. as shown at 37, 37 in Fig. 2. Having thus described my invention. claim:

1. In a pneumatic concentratiup table, a table deck composed a mineral septum,

' per'vious to air under pressure and provided with a series grooves along its upper surface filled with cementitious material, in combination with means for conveyingthe material to be separated across said table deck while subjected jointly to mechanical agitation and to air under pressure, substantially as described.

2. In a pneumatic concentrating table, a table deck composed of a mineral septunn pervious to air under pressure and provided with a series of grooves along its upper surface filled with cementitious material, in combination. with means for blowing air through the pervious areas of the table deck, means for agitating the table deck in an inclined position, and means for feeding the material to be separated upon the surface of thevtable deck, substantially as described.

3. In a pneumatic concentrating table, a table deck composed of a mineral septum. pervious to air under pressure, and provided with a series of parallel grooves along its upper surface filled with cementitious material, in'combination with means for agi tating said table deck in a transversely inclined position, means for blowing air through the pervious areas of said table deck, means for feeding the material to be separated upon the surface of said table deck, stratifying the minerals contained in the material thus fed into horizontal layers by the joint action of mechanical agitation,

and of air under pressure, and then separating the strata from each other by causing them to travel over the alternately cemented and uncemented areas of said table deck, substantially as described.

4. In a pneumatic"concentrating table, a

table deck composed of plates of accretcd mineral particles Forming a mineral septum and having a series ot parallel grooves filled with cement, in combination with means for passing air through the uncernented areas of said table deck, means for reciprocating the table in a transversely inclined position, means for feeding the material to be separated upon said table deck, stratifying the minerals thus fed into horizontal layers by the joint action of air'under pressure and of mechanical agitation. and then separating the strata by causing them to travel di- 1 agonally over the alternately cemented and uncemented areas of said table deck, substantially as described.

CLARENCE Q. PAYNE.

Witnesses:

WALTER, Jones, OLIVER M. PENNINGTON. 

